1. Field of the Invention
The present invention relates to an optical card apparatus arranged in such a manner that an action of relatively locating an optical card with respect to an optical head is retried on another track if the above-described action results in failure at the time of loading the optical card.
2. Description of the Related Art
An optical information recording medium, for example, an optical card, exhibits an advantage in that it can be easily carried because its size and the shape are the same as those of the credit card. Another advantage is that it has a large recording capacity and a low cost per card. Therefore, a variety of types of optical cards have been suggested recently to serve as next generation information recording medium.
An optical card apparatus serving as a conventional optical recording/reproducing apparatus, which uses an optical card of the above-described type, has been disclosed in Japanese Patent Laid-Open No. 2-154264 or U.S. Pat. No. 4,950,876.
As shown in FIG. 1, an optical card 1 for use in the above-described optical card apparatus is formed into a rectangular shape and having an optical recording portion 3 arranged in such a manner that a plurality of parallel straight tracks 2 are formed therein, the optical recording portion 3 serving as an optical recording region. In order to be capable of reading recorded data in the optical recording portion 3 regardless of the direction of scanning performed on the track, ID portions 3A and 3B, to which information denoting the address corresponding to each track, are formed at the two end portions, the ID portions 3A and 3B being formed in the opposite direction to each other. As a data portion 4 for recording data, the optical recording portion 3 is formed between the above-described ID portions 3A and 3B.
Therefore, when the optical card 1 is moved with respect to the position of an optical head 5 (see FIG. 2 or FIG. 3) in a direction, for example, from the left portion to the right portion along the track (hereinafter this direction is called a "forward direction"), the left ID portion 3A is read, while the right ID portion 3B is read when the optical card 1 is moved from the right portion to the left portion (hereinafter this direction is called a "reverse direction"). As a result, track address information which corresponds to the track can be recognized. In the structure arranged as described above, the two ID portions 3A and 3B respectively are formed at an inner portion at predetermined distance (for example, 4 mm) away from the end portion of the optical card 1 in order to prevent an influence of damage or a contamination of the card end portion and as well as to sufficiently stable the relative movement velocity in a direction of the track between the optical card 1 and the optical head 5.
As shown in FIG. 2, the optical card 1 is manually or automatically first inserted into a card holder 6 which has guide grooves formed in the two horizontal end portions thereof. As a result, a state of insertion (loading) as shown in FIG. 3 is realized. In the above-described state of loading, the optical head 5 is able to move in a direction of X. Since the optical card 1 is not located with respect to the position of the optical head 3 in the above-described state of loading, the above-described relative location must be compensated (an error taken place in loading of the optical card 1 must be compensated) so as to enable recording/reproducing data to and from an arbitrary track to be performed.
That is, the optical card 1 loaded into the card holder 6 is not accurately positioned with respect to the card holder 6 (or the optical head 5) such that the identification action can be performed. Therefore, access to an arbitrary track cannot be made in the above-described state. Therefore, it is necessary for a correcting action (also called a "presetting action") for correcting the relative position between the optical head 5 and the optical card 1 to be first performed.
The presetting action is performed in the following sequence arranged such that: the focus servo and the track servo are turned on when the optical card 1 is loaded into the card holder 6; the card holder 6 is moved to scan the track of the optical card 1 with beam spot S held in a tracking state; and thereby the ID portion formed on the optical card 1 is read.
However, in a case where there is a defect C such as dust or a flaw in the track (for example, a portion 2a shown in FIG. 3), to which presetting will be made, the above-described conventional example encounters a problem at the time of the presetting action in that the beam spot S for scanning the track deviates from a normal track servo state such that the beam spot S undesirably moves to a portion in the vicinity of the portion 2a of the track 2 (for example, the beam spot S undesirably scans a position deviated from pit columns on which information is recorded). If the retrial is made at the undesirable position to which the beam spot S has been moved, the presetting action cannot sometimes be performed in a case where there is a critical defect in the track.
If the above-described presetting action cannot be performed, the relative position between the optical card 1 and the optical head 5 cannot be located. As a result, access of an arbitrary track cannot be attained. Therefore, if the presetting action cannot be performed, recording/reproducing to and from the optical card 1 cannot be performed. In this case, neither recording nor reproducing can be performed and the optical card 1 is discharged from the card holder 6.